1. Technical Field
The present invention relates generally to molded containers with hinged lids, and, more particularly, to a cover and hinge assembly for large capacity refuse containers.
2. Background Art
Containers of this type, particularly in larger sizes on the order of 300 gallons, are particularly well suited for commercial use in receiving refuse. These refuse containers are capable of being handled by automated equipment, such as a side-loading refuse truck having a retractable lifting clamp which grasps, lifts and inverts the container to empty its contents.
The use of large plastic refuse containers with hinged lids is common to many settings, especially commercial settings. Such containers usually have lids pivotally fastened to the body by hinges which are mechanically fastened to the body and the lid. In addition, handles are usally fastened to the lid to facilitate the raising of the lid when manual access to the interior of the container is desired.
Refuse collections in major cities are labor intensive and as a result tend to be a major item in a city's budget. In order to reduce costs, the refuse collection industry has evolved from the highly labor intensive manual handling of each container to semi-automatic systems where the container is manually moved to the side of the compactor truck, gripped either semi-automatically or manually by lifting arms and then, at the touch of a control, lifted, inverted, emptied, and returned to the ground. The container then is disconnected and manually returned to curb side. Even more recently, fully automated systems have been developed which allow the driver to rapidly position the truck adjacent to the container at curb side, automatically extend an arm, grip container, raise, invert, empty, and return the container to curb side. The operation requires no labor except for the truck driver/operator and it is considerably faster than semi-automatic or automatic systems. The faster (short cycle time) systems increase the utilization of the compacting truck, which, in turn, reduces the capital expenditure requirements to service a given size population.
Both semi-automatic and automatic refuse collection systems require special container designs to allow interface with the lifting mechanism. The semi-automatic systems, however, do not require unusual closure designs since there is a man present in the area of the lift to unlatch or to remove a cover as is appropriate. The automated systems, however, must be equipped with a cover that will normally be closed; easily opened by the user; automatically opened when the container is inverted; automatically closed when the container is returned to curb side; and, be strong enough to withstand the rough handling that is inherent with a high speed automated lifting and emptying mechanism.
Since the containers must be especially designed for automated systems, mosts cities find it necessary to provide containers to the users at no cost or at a nominal fee. Containers, therefore, can be a major part of a city's capital expenditure on a newly implemented automated refuse collection system. Cost, durability, and use acceptance are all factors that affect the design of a typical automated refuse container system.
In some instances, such as multi-family dwellings, or in other densely populated areas it may be more efficient to use a larger container capable of filling the needs of two or more families. Such a container typically has a capacity of 300 to 400 gallons. These containers must be collected automatically with the same system as is used in the smaller single family dwelling containers. Therefore, the height of the container is restricted which in turn requires a relatively large top diameter. A typical top diameter for a large capacity refuse container would be 50-60 inches. A single cover large enough to close a top opening of this size with hinges located on the outer edge of the container has several drawbacks. Covers of a 50-60 inch diameter tend to be flexible and distort when lifted from one side by the user to insert refuse. Large covers tend to be structurally unstable and when they are closed abruptly or when a load is applied to the top of a cover it tends to distort and slip inside the container. Large covers tend to remain open after the container has been returned to curb side by an automated compactor since a large force is required to close the cover. Large covers that do remain open tend to move the center of gravity of the container and cause it to roll over when the container has been returned to curb side. Large covers tend to be heavy and, as a result, the hinge areas routinely tear out or fail in one manner or another. Large covers are subject to being opened by high winds, or, if opened partially by a user, the wind tends to catch the cover and upset the container. Finally, there is a tendency for the very large cover to be caught by the compactor blade or other structural members of the compactor truck.
Attempted solutions to the problems caused by a single, large, heavy cover for a large capacity refuse container have been to create multi-fold covers. Such a cover might have a hinge near the periphery that would be used when the container is being emptied, and a second hinge somewhere in the middle to allow the user to lift only a part of the cover to insert refuse. These containers are even less stable than full cover containers and there are inevitable structural failures as well as problems of the cover falling down into the container. Another attempted solution that has been tried is the use of a large cover hinged at the periphery and a smaller opening integral with the cover with a separate smaller cover that will be used by the resident for filling. These, however, have problems similar to those discussed above.
Additionally, all of the prior art large capacity refuse containers have problems with water infiltrating into the refuse container.
In the prior art, holes have conventionally been drilled to allow the hinge rod to pass through the hinge portions on the cover element and the container body. These drilled holes create high stress concentration areas in the body and the cover. It also creates a high bearing load on the hinge pin since the load is concentrated in the narrow areas of wall thickness in contact with the hinge pin. The present invention eliminates this problem by the use of an integral sleeve formed in the container body hinge portion.
The manufacture of prior art containers of the above-described type requires that extensive post-molding operations be carried out to mount the appropriate hardware on the container. For instance, to fasten the hinges, holes must be drilled in the body and lid. The hinges are then secured to the container by means of screws or other mechanical fasteners. To fasten the handles, holes must again be drilled and the handles then secured by means of screws.
The requirement of extensive post-molding assembly poses serious problems. First, it requires many separately manufactured parts. This large number of parts and the increased production time and labor required to assemble them increases cost and slows down production. Finally, the addition of so many parts weakens the container because of additional boring and the tendency of wear and fatigue of the material at mechanical connections. Thus, the finished product is less durable.
A strong need therefore exists for a container with a hinged lid that requires few additional parts and little assembly.